The automatic extraction, identification and determination of quinizarin in hydrocarbon oils

Abstract

Following the development of solvent-extraction systems for the analysis of effluents and water containing traces of detergent residues, a system for the extraction of quinizarin from samples of hydrocarbon oils suspected of containing duty rebated gas oil has been designed. This has been achieved by combining the principles of both systems described previously, and a unit has been constructed in prototype form. Identification and determination of the quinizarin present in the oil has been achieved by linking the solvent-extraction system with a flow-through cell of a recording spectrophotometer. Quinizarin is identified by the characteristic spectral pattern and determined by the peak height of the 521 nm peak.